About multiple input and output devices

With Softron's playout and ingest software you can record and/or playout multiple channels on the same computer. There are different ways to have multiple in / out:


  1. with one multichannel device
  2. with multiple devices to reach the number of in/out you need


We would recommend you to use one device with multiple i/o) because these devices are meant for that (as the M|80, M|62 or M|44). Check the article that lists the devices supported, the number of channels they support and if they can do keying.




Can I use all the connectors on my device?


In the article that lists the devices supported by our products you will see some mentions about Full duplex, dual or quad link. All of this is related to the fact that the number of connectors on one device does not tell you what it can do. For example some devices have 2 input connectors and 2 output connectors, but they can in fact just either record one channel or playout one channel.


Here are the explanations.


Dual and Quad Link


The multiple input and output connectors can be used to output to some formats that are not supported by the type of connector. Nowadays the most used example is when you want to work with 4K signals by using 3G connectors. 3G is limited to 1080p60 signals, so to achieve 4K at 60p, 4 x 3G SDI signals are grouped together.


  • Quad link of 3G connectors to reach 4K60p
  • Quad link of HD connectors to reach 4K30p
  • Dual link of 3G connectors to reach 2K signals 




Also, the 2 output connectors can be used to output the fill and the key signal when you choose to output using external key.


Full Duplex

This is mainly used for Blackmagic-Design devices. Indeed some Blackmagic-Design devices are "Full-duplex" and others are not.


When a device is "Full Duplex", it means that you  can use simultaneously the input and the output. For example with the UltraStudio 4K, you can use the card for 1 in and 1 out at the same time.


When a device is NOT "Full Duplex" it means that the connectors will be either in or out. For example, the AJA Io 4K has 4 different connectors. And a maximum of 4 inputs or 4 outputs, but not in Full Duplex so you can not use the 4 inputs and the 4 outputs a the same time. You will have the following combinations possible:


  • 4 in
  • 3 in - 1 out
  • 2 in - 2 out
  • 1 in - 3 out
  • 4 out




You need analog audio- What can you do ?


All the cards that support multiple inputs or outputs only do that using SDI with embedded audio. Softron users who need multiple inputs or outputs with analog audio, have a few solutions.


With MovieRecorder 4


In MovieRecorder 4 we introduced the support of external audio device, so any audio input that is available to the macOS will be available in MovieRecorder. That is probably the easiest method for multichannel video input with analog audio.


With all other software


Then you either have to:


  • use embedder/de-embedder, to embed or de-embed audio in/out of the SDI
  • use multiple single i/o devices that have analog audio. 




Different combinations


With our applications we don't limit any combinations so you can use:


  • multiple identical devices (for example connect multiple AJA Io T-Tap)
  • multiple devices from the same brand, but different model (for example a Blackmagic-Design UltraStudio Mini Monitor with a Blackmagic-Design UltraStudio 4K)
  • multiple devices from different brands (for example a Blackmagic-Design UltraStudio Mini Monitor with an AJA T-Tap, and an M|44).


At the time of writing, we don't know of any incompatibility issues between devices or drivers, but this is something that we can not guarantee will always be. Indeed, this is something that is handled by the devices manufacturers. They usually guarantee that multiple identical devices will work fine. If it's a different model, it may be more difficult to get the guarantee, but once you say you want to mix with a different (competitive) brand, then you never can have that guarantee.


So it is up to you. You can get in touch with the device manufacturer and/or us to check if there are any known issue, but you'll understand that we can't validate every single combination that may exist.




How is the order of the devices maintained?


If the devices that you connect are different (different model or brand), then it's easy, and we can always identify each of them. But when you connect multiple identical devices, we will append a number to each of them [1], [2], ... and we must be able to identify which one is which across restarts of the application, so the output/input 1 is always the same device. If the device has a unique identifier it is easy, but if it does not have one, it can be tricky.




For devices that have a unique identifier


Most video device have a unique identifier (kind of its serial number). All AJA and M|family devices have a unique identifier. Only some Blackmagic-Design devices have that identifier.


When you configure OnTheAir Video, OnTheAir CG, OnTheAir Node, or MovieRecorder, we store in the preferences that unique identifier so we are always sure to output/input using the correct device.


This means that for example if you own 2 AJA T-Tap, if you connect both of them, every time you will restart your Mac, or MovieRecorder, even if you change the way they are plugged in Thunderbolt to your Mac, every time the configuration will remain and we will output to the correct device.


But this also means that for example if you connect  one of them to your computer and configure it, it will work fine. But then later on you forgot which device was connected and connect the other AJA T-Tap, the preference will show that the device is <Missing> as it does not have the same unique identifier.




Devices that don't have a unique identifier


At the time of writing, all Blackmagic-Design devices that were released after the UltraStudio 4K  (UltraStudio 4K, Decklink 4K ...) have that unique identifier. For these devices, the order of inputs and outputs will always remain the same and will behave as explained above. For example, if you connect multiple UltraStudio 4K to your Mac, and start MovieRecorder, the input number 1 and input number 2 will always correspond to the same device.


For the devices that do not have a unique identifier, the order of the devices is set by the way they are connected to the Mac. So as long as you don't plug or unplug anything new in the Thunderbolt connectors (or change the order of the PCI cards), the devices order will remain the same.


But let's say you have 2 UltraStudio Mini Recorders, if you start MovieRecorder, and configure your 2 sources, in MovieRecorder, they will be named "UltraStudio Mini Recorder (1)" and UltraStudio Mini Recorder (2)". If now you connect an external hard drive to your computer and restart MovieRecorder, both device will most probably show as <Missing> and you will have to select them again and make sure to select the good one knowing that their order may have changed. This is because the configuration of your Thunderbolt buses have been changed, and thus now there is no way for us to identify which device is which.

You can check which model has a unique identifier in the article that shows the compatible video devices.



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